Skip to main content

Web Publications


AAVSO Alert Notice 401: Monitoring of EX Hya and DQ Her AAVSO HOME > publications > alert notice

AAVSO Alert Notice 401

Monitoring of EX Hya and DQ Her
August 13, 2009

Kunegunda Belle, Don Hoard and Steve Howell are observing
two cataclysmic variables with Spitzer during the next couple
of weeks.  They request ground-based light curves spanning
the observation intervals so that they can identify the
state each variable is in during the Spitzer visits.


1. EX HYA (12:52:24.20, -29:14:56.0, AUID 000-BBT-323)

The observations for EX Hya are scheduled for:

2009-08-18  19:25:01.1 UT 3.6micron single exposure
2009-08-18  19:26:52.9 UT 4.5micron light curve

EX Hya is an eclipsing system with 98-minute period and normally
resides about V=13.  The eclipses are only a magnitude or so in depth.


2. DQ HER (18:07:30.20, +45:51:32.0, AUID 000-BCB-341)

The observations for DQ Her are scheduled for:

2009-08-23  03:25:13.8 UT 3.6micron single exposure
2009-08-23  03:27:36.5 UT 4.5micron light curve

DQ Her normally sits at V=14.5, but remember that this is
a deeply eclipsing system (280 minute period) and during
eclipse it will dip below V=18.


The researchers request that you obtain a time series
light curve, preferably in V-band, starting at least one day
prior to and continuing one day after the Spitzer visit to the
appropriate field.  Expose long enough to get signal/noise = 30
in each individual frame.

This AAVSO Alert Notice was prepared by A. Henden


-------------------------------------------
SUBMIT OBSERVATIONS TO THE AAVSO

Information on submitting observations to the AAVSO may be found at:

http://www.aavso.org/observing/submit/

ALERT NOTICE ARCHIVE AND SUBSCRIPTION INFORMATION

An Alert Notice archive is available at the following URL:
http://www.aavso.org/publications/alerts/

Subscribing and Unsubscribing may be done at the following URL:
http://www.aavso.org/publications/email/

Keywords:
AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484